Synthesis Of Metal Nanoparticles Research Articles

Biosynthesis of Silver and Gold Nanoparticles Using Geum urbanum L. Rhizome Extracts and Their Biological Efficiency

AbstractThe present study evaluates the biosynthesis of AgNPs and AuNPs using aqueous and ethanolic Geum urbanum L. rhizome extracts. The biosynthesized metal nanoparticles (MNPs) were characterized using UV-Vis spectroscopy, FTIR, DLS, SEM, EDX, and TEM. The UV-Vis spectra confirmed the synthesis of AgNPs and AuNPs through peaks corresponding to the surface plasmon effect of metallic Ag (400–430 nm) and Au (530–570 nm). FTIR analysis indicated that alcohols, phenols, proteins, and carbohydrates from G. urbanum rhizome extracts composition are involved in MNPs synthesis. In DLS analysis, AgNPs (34.26–41.14 nm) showed smaller hydrodynamic diameters than AuNPs (46.26–70.29 nm). At the same time, all values for zeta potential were negative, between − 21 and − 13 mV, suggesting good stabilities for all the colloidal MNPs systems in dispersion. TEM analysis showed that the biosynthesized AgNPs had a spherical morphology, while AuNPs were quasi-spherical, polygonal, and triangular. According to TEM data, AgNPs synthesized using aqueous and ethanolic G. urbanum rhizome extracts were characterized by mean diameters of 9.82 ± 3.68 and 14.29 ± 3.46 nm, while AuNPs by 15.88 ± 6.28 and 24.89 ± 10.75 nm, respectively. EDX analysis confirmed the presence of metallic Ag and Au in the MNPs composition by detecting strong signals at 3 (AgNPs) and 2.2 keW (AuNPs). In disc diffusion assay, MNPs showed good antimicrobial activity against Gram-positive (S. aureus MSSA, S. aureus MRSA, S. epidermidis) and Gram-negative (E. coli, P. aeruginosa, K. pneumoniae) bacteria and yeasts (C. albicans). AgNPs and AuNPs were also characterized by a significant antioxidant potential, evaluated through in vitro assays (lipoxygenase inhibition, DPPH radical scavenging activity, metal ion chelating activity, and hydroxyl radical scavenging assays). An overall better activity was obtained for the ethanolic G. urbanum rhizome extract and its derived AgNPs (EC50 = 34.2 ± 1.86 mg/mL in lipoxygenase inhibition assay). Therefore, the G. urbanum rhizome extracts proved to be excellent sources for biologically active AgNPs and AuNPs.

An acoustofluidic picoinjector

Droplet microfluidics has emerged as a valuable technology for a multitude of chemical and biomedical applications, offering the capability to create independent microenvironments for high-throughput assays. Central to numerous droplet microfluidic applications is the picoinjection of materials into individual droplets, yet existing picoinjection methods often exhibit high power requirements, lack biocompatibility, and/or suffer from limited controllability. Here, we present an acoustofluidic picoinjector that generates acoustic pressure at the droplet interface to enable on-demand, energy-efficient, and biocompatible injection at high precision. We validate our platform by performing acid-base titrations by iteratively injecting picoliter volume reagents into droplets to induce pH transitions detectable by color change in solution. Additionally, we demonstrate the versatility of the acoustofluidic picoinjector in the synthesis of metallic nanoparticles, yielding highly monodisperse and reproducible particle morphologies compared to conventional bulk-phase techniques. By facilitating controlled delivery of reagents or biological samples with unparalleled accuracy, acoustofluidic picoinjection broadens the utility of droplet microfluidics for a myriad of applications in chemical and biological research.

Synthesis of Metallic and Metal Oxide Nanoparticles Using Homopolymers as Solid Templates: Luminescent Properties of the Eu+3 Nanoparticle Products

Starting from poly(4-vinylpyridine) ((P4VP)n), poly(2-vinylpyridine) ((P2VP)n), and [N=P(O2CH2CF3)]m-b-P2VP20 block copolymers, a series of metal-containing homopolymers, (P4VP)n⊕MXm, (P2VP)n⊕MXm, and [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm MXm = PtCl2, ZnCl2, and Eu(NO3)3, have been successfully prepared by using a direct and simple solution methodology. Solid-state pyrolysis of the prepared metal-containing polymeric precursors led to the formation of a variety of different metallic and metal oxide nanoparticles (Pt, ZnO, Eu2O3, and EuPO4) depending on the composition and nature of the polymeric template precursor. Thus, whereas Eu2O3 nanostructures were obtained from europium-containing homopolymers ((P4VP)n⊕MXm and (P2VP)n⊕MXm), EuPO4 nanostructures were achieved using phosphorus-containing block copolymer precursors, [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm with MXm = Eu(NO3)3. Importantly, and although both Eu2O3 and EuPO4 nanostructures exhibited a strong luminescence emission, these were strongly influenced by the nature and composition of the macromolecular metal-containing polymer template. Thus, for P2VP europium-containing homopolymers ((P4VP)n⊕MXm and (P2VP)n⊕MXm), the highest emission intensity corresponded to the lowest-molecular-weight homopolymer template, [P4VP(Eu(NO3)3]6000, whereas the opposite behavior was observed when block copolymer precursors, [N=P(O2CH2CF3)]m-b-P2VP20]⊕MXm MXm= Eu(NO3)3, were used (highest emission intensity corresponded to [N=P(O2CH2CF3)]100-b-[P2VP(Eu(NO3)3)x]20). The intensity ratio of the emission transitions: 5D0 → 7F2/5D0 → 7F1, suggested a different symmetry around the Eu3+ ions depending on the nature of the polymeric precursor, which also influenced the sizes of the prepared Pt°, ZnO, Eu2O3, and EuPO4 nanostructures.

Antimicrobial Activity of Green Synthesized Silver and Copper Oxide Nanoparticles against the Foodborne Pathogen Campylobacter jejuni.

Campylobacter jejuni is a major cause of global foodborne illnesses. To develop alternative antimicrobial strategies against C. jejuni, this study designed and optimized the green synthesis of metallic nanoparticles (NPs) with intracellular components of the medicinal fungus Ganoderma sessile to provide the needed reducing and stabilizing agents. NPs were characterized by transmission electron microscopy and dynamic light scattering, and the quasi-spherical NPs had sizes of 2.9 ± 0.9 nm for the copper oxide NPs and 14.7 ± 0.6 nm for the silver NPs. Surface charge assessment revealed zeta potentials of -21.0 ± 6.5 mV and -24.4 ± 7.9 mV for the copper oxide and silver NPs, respectively. The growth inhibition of C. jejuni by the NPs occurred through attachment to the outer cell membrane and subsequent intracellular internalization and resulted in minimum inhibitory concentrations of the silver NPs at 6 µg/mL and copper oxide NPs at 10 µg/mL. On the other hand, a differential ROS production caused by silver and copper NPs was observed. In summary, this research presents the first demonstration of using green synthesis with the medicinal fungus G. sessile to produce metallic NPs that effectively inhibit C. jejuni growth, providing a sustainable and effective approach to the traditional use of antimicrobials.

Green Synthesis of Metallic Nanoparticles from Quercus Bark Extracts: Characterization and Functional Properties.

Quercus species are utilized for their durable wood, providing sustenance for wildlife, conserving biodiversity, and contributing ecological, medicinal, and esthetic benefits to ecosystems and landscapes. In this study, we aimed to use the bark of three Quercus species (Q. dalechampi, Q. fraineto, and Q. petraea) for the synthesis of silver and gold nanoparticles (AgNPs and AuNPs). The aqueous extracts from the bark of Quercus sp. acted both as reducing and stabilizing agent, facilitating the rapid synthesis of AuNPs (AuQD, AuQF, and AuQP) and AgNPs (AgQD, AgQF, and AgQP). The obtained nanoparticles were characterized using UV-vis spectroscopy, TEM, DLS, and FTIR. Characterizations revealed that the nanoparticles exhibited a variety of shapes, such as polygonal, triangular, and spherical forms, with sizes ranging between 14 and 24 nm for AuNPs and 45-70 nm for AgNPs. The total phenolic content was assessed through spectroscopic methods, while several individual phenolic compounds were identified and quantified using UPLC-PDA. Furthermore, we assessed the antioxidant, antibacterial, and antifungal capacities of AuNPs, AgNPs, and raw extracts. The highest antioxidant activity was observed for raw extracts, followed by AgNPs and AuNPs, while the most potent antibacterial and antifungal activity was observed in AgQP. Moreover, cytotoxicity was examined in a human keratinocyte cell line (HaCaT). The results indicated no cytotoxic effects for AuNPs, while AgNPs and the raw extracts exhibited cytotoxic effects after 48 h of incubation. This research underscores the multifaceted utility of Quercus bark extracts in the green synthesis of metallic nanoparticles and their subsequent bioactivity assessment, suggesting promising perspectives for their application in various fields while urging cautious consideration of their cytotoxic implications.

Green synthesis of silver nanoparticles using Senna alexandrina leaf extracts and their antibacterial, larvicidal, nanotoxicity and photocatalytic activity

Biological synthesis of metal nanoparticles has been discovered in recent years, and they have been effectively manufactured and studied from diverse plant extracts. Recent research has shown that nanoparticles have extremely promising antibacterial, larvicidal and anticancer effects. The current study aimed to synthesize Senna alexandrina leaf extract-mediated silver nanoparticles (SA-AgNPs) as are reducing and capping agent. The produced SA-AgNPs were characterized by using UV–visible spectroscopy, Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and Field emission scanning electron microscopy with energy dispersive spectroscopy (FESEM-EDS). The result showed synthesized SA-AgNPs were confirmed by UV–visible spectroscopy with 440 nm absorption. FT-IR analysis shows the presence of phosphine, primary amines, carboxylic acids, ether, and alkyl halides biomolecules in both plant extract and SA-AgNPs. XRD findings revealed the crystalline structures of produced SA-AgNPs. The spherical shape of SA-AgNPs with an average size of 20–35 nm was confirmed using FESEM. The SA-AgNPs show better antibacterial activity against E. coli (18.0 ± 0.25 mm), S. aureus (17.2 ± 0.36 mm), P. aeruginosa (16.8 ± 0.12 mm), and leaf extract of S. alexandrina showed minimal antibacterial activity. The SA-AgNPs show 100 % mortality for both Cx. quinquefasciatus and Ae. aegypti after 48 hrs. The brine shrimp lethal assay of the SA-AgNPs shows 100 % at 30 µg after 24 hrs of brine shrimp which indicated the presence of cytotoxicity this suggests that produced SA-AgNPs are slightly toxic. The photocatalytic activity was also tested using reactive orange 16 (RO16) and phenol red (PR) with the percentage of degradation being about 93.95 % and 92.91 % respectively. These results suggest that biosynthesized SA-AgNPs have promising properties that can be used as an effective biomedical and environmental protectant.

Lignin: A multifunctional and sustainable photothermal material for solar-driven thermoelectric generation and desalination

The abundant aromatic ring structure and a large number of oxygen-containing functional groups in the lignin offer the possibility of achieving excellent photothermal conversion ability and modulating the synthesis of metal nanoparticles. Herein, three kinds of the lignin with different functional group content were employed to investigate the potential influence on the particle size and the solution stability of the CuS through two reaction pathways. The result of various characterizations indicated that the higher the oxygen-containing functional group content (4.83 mmol/g) of lignin, the smaller the size of CuS nanoparticles (∼80 nm) in solution. And the smaller and homogeneously dispersed CuS offered a higher surface temperature for the solar-driven heat-generating materials. The regulation mechanism was also proposed based on the result of the molecular dynamics simulation and DFT calculation. Subsequently, the photothermal film (Route2 DTAL-PVA-30) and solar-driven aerogel evaporator (Route2 DTAL-AG3) were successfully prepared using the lignin-guided stabilization solution of CuS nanoparticles. The photothermal conversion efficiency of 49.43 % and the equilibrium voltage of 266 mV can be achieved by the Route2 DTAL-PVA-30 under 1 sun using a thermoelectric generator. The Route2 DTAL-AG3 exhibited promising salt-rejecting property and outstanding acid and alkali resistance performance, reaching an evaporation rate of up to 1.93 kg/(m2 h) in the 3.5 wt% seawater under 1sun. This work may provide a novel strategy to realize the regulatory role of lignin in the metal synthesis and achieve the high value-added applications of the lignin.

Bespoke Metal Nanoparticle Synthesis at Room Temperature and Discovery of Chemical Knowledge on Nanoparticle Growth via Autonomous Experimentations (Adv. Funct. Mater. 27/2024)

Bespoke Metal Nanoparticle Synthesis at Room Temperature and Discovery of Chemical Knowledge on Nanoparticle Growth via Autonomous Experimentations (Adv. Funct. Mater. 27/2024)

Antioxidant, antiglycation, and antibacterial of copper oxide nanoparticles synthesized using Caesalpinia Sappan extract.

Synthesis of metal nanoparticles using plant extracts is environmentally friendly and of increasing interest. However, not all plant extracts can meet successfully on the synthesis. Therefore, searching for the high potential extracts that can reduce the metal salt precursor in the synthesis reaction is essential. The present study explores the synthesis of copper oxide nanoparticles (CuONPs) using Caesalpinia sappan heartwood extract. Phytochemical analysis and determination of the total phenolic content of the extract were performed before use as a reducing agent. Under the suitable synthesized condition, a color change in the color of the solutions to brown confirmed the formation of CuONPs. The obtained CuONPs were confirmed using ultraviolet-visible spectroscopy, photon correlation spectroscopy, X-ray diffraction, scanning electron microscope, energy dispersive X-ray, and Fourier transform infrared analysis. The synthesized CuONPs investigated for antioxidant, antiglycation, and antibacterial activities. CuONPs possessed antioxidant activities by quenching free radicals with an IC50 value of 63.35 µg/mL and reducing activity with an EC range of 3.19-10.27 mM/mg. CuONPs also inhibited the formation of advanced glycation end products in the bovine serum albumin/ribose model with an IC50 value of 17.05 µg/mL. In addition, CuONPs showed inhibition of human pathogens, including Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, and prevention of biofilm formation and biofilm eradication, with maximum inhibition of approx. 75%. Our findings suggest that C. sappan extract can be used to obtain highly bioactive CuONPs for the development of certain medical devices and therapeutic agents.

METHODS OF BIOSYNTHESIS OF METAL NANOPARTICLES, PROSPECTS OF APPLICATION IN CROP PRODUCTION

The main objective of this review is to consider the environmentally ecological synthesis of nanoparticles with the help o f plants and the importance of this approach, application areas. It can be said that metal nanoparticles take place in all spheres of human life, such as food security, medicine, veterinary medicine, agriculture, environmental protection, energy, electronics. Currently, the development of environmentally friendly methods for the chemical and biological synthesis of metal nanoparticles is a pressing issue attracting significant attention from scientists worldwide. In the biological synthesis of metals, various living organisms, fungi, algae, and plants can be used. And the importance of using these nanoparticles in crop production is still being actively studied. In our work, we reviewed articles by scientists from a number of countries who have widely used this method in various industries. The biocompatibility and stability of metal nanoparticles produced through "green synthesis" have been demonstrated in numerous studies. A thorough literature review also examined the plants used in this synthesis process and the various applications of the synthesized metal nanoparticles based on their properties. Tһe topic of this revew is one of the relevant for Kazakhstan, therefore, the prospects of using metal nanoparticles in agricultural crop production and as growth stimulants and in plant protection are being considered in the country.

Antifungal screening of silver nanoparticles biosynthesized by Aliinostoc oryzae against plant pathogenic fungi

Metallic nanoparticles exhibit exceptional antifungal characteristics and are regarded as a feasible substitute for the control of diverse fungus species. Cyanobacteria have received significant recognition as nanobiofactories across all identified taxa owing to their remarkable ability to assimilate toxins from their environment. Consequently, cyanobacteria-mediated metal nanoparticle synthesis represents an innovative strategy for biological regulation. The present investigation assessed the effectiveness of silver nanoparticles (AgNPs) manufactured using Iranian cyanobacteria, Aliinostoc oryzae, as fungus inhibitors against plant pathogens. For this purpose, the cyanobacterial strain was cultured in BG-110, medium and AgNPs were synthesized by the wet biomass method. The AgNPs were then characterized by UV–visible spectroscopy, DLS, zeta potential, field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM), fourier transform infrared spectroscopy (FT-IR), and X-ray diffraction tests. Afterwards, the antifungal activities of fabricated nanoparticles were tested against fungal strains of Botrytis cinerea, Alternaria alternate, Colletotrichum gloeosporioides, Fusarium oxysporum, Phytophthora capsici, Pythium ultimum, and Rhizopus stolonifera. The results of UV–vis spectrophotometry confirmed the AgNP formation with a color change to dark brown at a wavelength range of 430–432 nm. Morphological examination through the Field Emission Scanning Electron Microscope (FESEM) indicated irregular and spherical shapes. X-ray diffraction (XRD) results showed a cubic crystalline structure with a crystallite size of approximately 20 nm. The zeta potential and electrophoretic mobility of the nanoparticles were −33.67 mV and 0.35 Vs/cm2, respectively. Fourier-transform infrared spectroscopy (FTIR) analysis identified a sharp and intense peak at 538 cm−1, corresponding to the stretching vibration of silver nanoparticle bonds. Based on the antifungal activity results, Pythium ultimum had the largest growth inhibition zone. On the other hand, Colletotrichum gloeosporioides and Alternaria alternate had the smallest inhibition zones. These findings demonstrate the ability to characterize and test AgNPs produced by Iranian cyanobacteria for their antifungal activity.

In-situ modification of nickel electrode by coupling the microbial corrosion and microbial reduction using Shewanella oneidensis for enhanced electrocatalysis

Shewanella oneidensis is a facultative anaerobe with the ability to use different terminal electron donors and acceptors. Therefore, S. oneidensis can be used either as an oxidizing agent for microbial corrosion of metals or as a reducing agent for microbial synthesis of metal nanoparticles depending on the metal type. Herein, we have shown that S. oneidensis MR-1 can be used for both microbial corrosion of nickel foam (NF) and microbial synthesis of Ni nanoparticles under environmentally benign conditions. It is found that S. oneidensis MR-1 can accelerate the corrosion process to form metal hydroxides on the surface of NF in the presence of Fe3+, and the obtained electrode shows improved electrocatalytic activity toward oxygen evolution reaction with an overpotential of 0.265 V to achieve a current density of 10 mA cm−2. However, the corrosion process of NF by S. oneidensis MR-1 is severely inhibited in the presence of Fe2+. In addition, aside from the corrosion process of NF, we have for the first time shown that Ni nanoparticles can be synthesized by the reduction of Ni2+ ions using S. oneidensis MR-1. The results show that the microbial energy metabolism of S. oneidensis MR-1 facilitates the electron transfer from electron-donating NF to the electron-accepting metal ions (Fe3+, Ni2+) across the microbes, coupling the corrosion process (Ni → Ni2+) and metal ions reductions (Fe3+ → Fe2+, Ni2+ → Ni), which demonstrates great potential for in-situ modification of electrode with microorganism and provides new avenue for electrode fabrication.

Study on Synthesis and Characterization of Metal Nanoparticles for Biomedical Applications

In this research paper, I have thoroughly described about the topic “Study on Synthesis and Characterization of Metal Nanoparticles for Biomedical Applications.” Metal nanoparticles have emerged as promising candidates for a myriad of biomedical applications due to their unique physicochemical properties, offering a wide array of opportunities for innovation in healthcare. This abstract discusses metal nanoparticle creation, characterization, and biomedical applications. Chemical reduction, green synthesis, physical deposition, and biological methods allow fine nanoparticle size, shape, and composition control for biomedical applications. TEM, DLS, XRD, UV-Vis, FTIR, SEM, and TGA reveal metal nanoparticles' structural, chemical, and optical properties. Metal nanoparticles are used in medication delivery, imaging contrast, targeted therapy, and diagnostics. Their small size, large surface area-to-volume ratio, and tunable optical properties make them suitable for drug delivery, where they can encapsulate and release therapeutic substances at precise body regions. Metal nanoparticles also improve illness identification and monitoring in MRI, CT, and fluorescence imaging by acting as contrast agents. They provide innovative cancer and microbial infection treatments due to their photothermal and antibacterial characteristics. Metal nanoparticles also find utility in biosensing applications, facilitating the detection of biomolecules and disease biomarkers with high sensitivity and specificity. Overall, the synthesis and characterization of metal nanoparticles represent a vibrant area of research with significant implications for advancing healthcare technologies, offering versatile platforms for addressing key challenges in diagnostics, therapeutics, and imaging in biomedicine.

Photocatalysis-enhanced synthesis and stabilization of silver nanoparticles by methanol-based phytochemicals extract of Trigonella foenum-graecum seeds

Trigonella foenum-graecum is an economically important plant that has significant nutraceutical properties. Various parts of the plant have previously been reported to synthesize metal nanoparticles. However, the seeds of the plant have limited potential to synthesize metal nanoparticles. Green synthesis of silver nanoparticles requires phytochemicals as reducing and metal chelating agents, in addition to the stabilizing agents that play critical role in nanoparticles stabilization. The quantitative analysis of the methanol extract of the seeds suggest that the extract has significant antioxidant activity and reducing potential which is comparable to that of ascorbic acid. Likewise, GCMS data of the extract identified several phytochemical components that have nanoparticles stabilizing potential. Evidently, the extract indeed synthesized silver nanoparticles in dark, albeit in very low quantity. This limitation of low quantity of nanoparticles synthesis was overcome by photocatalysis. The rate of nanoparticles synthesis increased significantly with increase in the intensity of the white light-emitting diode (LED) light. Furthermore, the photocatalytic effect of the white light also has significant impact on the physicochemical characterisation of the nanoparticles. Particle size, nanoparticles yield and elemental analysis demonstrated that the 2000 lumens white LED light is optimum for photocatalysis as compared to the 250 lumens and 825 lumens light. However, the stability of nanoparticles is not influenced by photoirradiation, and is rather controlled by the phytochemical composition of the extract. Methanol extract of the seeds significantly enhanced the stability of the silver nanoparticles irrespective of the light intensities used for photocatalysis.

Bioactive nanoparticles derived from marine brown seaweeds and their biological applications: a review.

The biosynthesis of novel nanoparticles with varied morphologies, which has good implications for their biological capabilities, has attracted increasing attention in the field of nanotechnology. Bioactive compounds present in the extract of fungi, bacteria, plants and algae are responsible for nanoparticle synthesis. In comparison to other biological resources, brown seaweeds can also be useful to convert metal ions to metal nanoparticles because of the presence of richer bioactive chemicals. Carbohydrates, proteins, polysaccharides, vitamins, enzymes, pigments, and secondary metabolites in brown seaweeds act as natural reducing, capping, and stabilizing agents in the nanoparticle's synthesis. There are around 2000 species of seaweed that dominate marine resources, but only a few have been reported for nanoparticle synthesis. The presence of bioactive chemicals in the biosynthesized metal nanoparticles confers biological activity. The biosynthesized metal and non-metal nanoparticles from brown seaweeds possess different biological activities because of their different physiochemical properties. Compared with terrestrial resources, marine resources are not much explored for nanoparticle synthesis. To confirm their morphology, characterization methods are used, such as absorption spectrophotometer, X-ray diffraction, Fourier transforms infrared spectroscopy, scanning electron microscope, and transmission electron microscopy. This review attempts to include the vital role of brown seaweed in the synthesis of metal and non-metal nanoparticles, as well as the method of synthesis and biological applications such as anticancer, antibacterial, antioxidant, anti-diabetic, and other functions.

Facile and sustainable synthesis of metal nanoparticles (Ag, Fe, Cu, and Zn) using polyamide and polyhydrazide

Facile and sustainable synthesis of metal nanoparticles (Ag, Fe, Cu, and Zn) using polyamide and polyhydrazide

Exploring the Potential of Halotolerant Actinomycetes from Rann of Kutch, India: A Study on the Synthesis, Characterization, and Biomedical Applications of Silver Nanoparticles.

A tremendous increase in the green synthesis of metallic nanoparticles has been noticed in the last decades, which is due to their unique properties at the nano dimension. The present research work deals with synthesis mediated by the actinomycete Streptomyces tendae of silver nanoparticles (AgNPs), isolated from Little and Greater Rann of Kutch, India. The confirmation of the formation of AgNPs by the actinomycetes was carried out by using a UV-Vis spectrophotometer where an absorbance peak was obtained at 420 nm. The X-ray diffraction pattern demonstrated five characteristic diffraction peaks indexed at the lattice plane (111), (200), (231), (222), and (220). Fourier transform infrared showed typical bands at 531 to 1635, 2111, and 3328 cm-1. Scanning electron microscopy shows that the spherical-shaped AgNPs particles have diameters in the range of 40 to 90 nm. The particle size analysis displayed the mean particle size of AgNPs in aqueous medium, which was about 55 nm (±27 nm), bearing a negative charge on their surfaces. The potential of the S. tendae-mediated synthesized AgNPs was evaluated for their antimicrobial, anti-methicillin-resistant Staphylococcus aureus (MRSA), anti-biofilm, and anti-oxidant activity. The maximum inhibitory effect was observed against Pseudomonas aeruginosa at (8 µg/mL), followed by Escherichia coli and Aspergillus niger at (32 µg/mL), and against Candida albicans (64 µg/mL), whereas Bacillus subtilis (128 µg/mL) and Staphylococcus aureus (256 µg/mL) were much less sensitive to AgNPs. The biosynthesized AgNPs displayed activity against MRSA, and the free radical scavenging activity was observed with an increase in the dosage of AgNPs from 25 to 200 µg/mL. AgNPs in combination with ampicillin displayed inhibition of the development of biofilm in Pseudomonas aeruginosa and Streptococcus pneumoniae at 98% and 83%, respectively. AgNPs were also successfully coated on the surface of cotton to prepare antimicrobial surgical cotton, which demonstrated inhibitory action against Bacillus subtilis (15 mm) and Escherichia coli (12 mm). The present research integrates microbiology, nanotechnology, and biomedical science to formulate environmentally friendly antimicrobial materials using halotolerant actinomycetes, evolving green nanotechnology in the biomedical field. Moreover, this study broadens the understanding of halotolerant actinomycetes and their potential and opens possibilities for formulating new antimicrobial products and therapies.

Biosynthesis of zinc oxide nanoparticles using water hyacinth extracts: Characterization, evaluation of antimicrobial and dye removal

In nanobiotechnology, synthesizing metal nanoparticles (NPs) using plant extracts has recently been increasing because of eco-friendly and low-cost methods. For this work, zinc oxide nanoparticles (ZnO NPs) have been synthesized by biosynthesis process using water hyacinth extracts (WHE). The water hyacinth (WH) was chosen because the WH is fast-growing and the most toxic aquatic plant in the world. Therefore, this work aims to apply these WHE to be a precursor in the biosynthesis of ZnO NPs (ZnOBio-NPs) based on the research of a sustainable environment. The ZnO NPs synthesized by the WHE were investigated for their antibacterial and photocatalytic activities. An UV-Vis spectrum showed a specific absorbance peak around 362 nm with an average band gap of 3.22 eV. As the result, TEM analysis revealed a triangle structure with an average size of about 64.05 nm. The peaks of XRD analysis show a hexagonal wurtzite structure. The ZnO NPs synthesized by the WHE showed higher antibacterial activity against S. aureus better than E. coli. It is interesting to note that the ZnOBio-NPs synthesized from the WHE can have an anti P. acnes (JB7) with a minimum inhibitory concentration (MIC) and a minimum bactericidal concentration (MBC) equal to 50 µg∙mL‒1 and 200 µg∙mL‒1, respectively. In addition, the ZnOBio-NPs also can effectively remove more than 90% of the malachite green within 180 minutes with extremely high reuse.

Ionic Liquids as an Efficient Reaction Medium in the Robust Synthesis of ZnO Nanoparticles

Aim:: Ionic liquids belong to the class of green solvents and are distinguished by their simple yet distinctive physical properties that are related to their structure. These properties include their remarkable thermal stability, exceptional thermal conductivity, and negligible vapor pressure. Additionally, they are suitable and inert for a wide range of catalytic applications. Zinc Oxide Nanoparticles (ZnO-NPs) have been considered a cost-effective choice that requires modest reaction conditions to provide a high yield of the required products with remarkable selectivity in a short amount of time. Consequently, an investigation into the synthesis of ZnO-NPs in an ionic liquid medium has been attempted in the current work. Background:: The synthesis of metal nanoparticles using highly tunable ionic liquids is being investigated for many pharmacological applications and their usage in catalysis. Objectives:: In this context, the current work has used the co-precipitation approach to synthesize ZnO-NPs. The production of ZnO nanoparticles with a range of morphologies utilizing an imidazolium ionic liquid system has been the main topic of discussion. Methods:: The co-precipitation method has successfully been administered for the synthesis of morphologically diverse nano-crystalline ZnO particles using different ionic liquids, such as 1-propyl- 3-methylimidazolium bromide (pmim)(Br), 1-butyl-3-methylimidazolium bromide ([bmim][Br]), and 1-hexyl-3-methylimidazolium bromide (hmim)(Br) as an additive Results:: Modern analytical tools, including X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and FT-IR absorption spectroscopy have been employed to confirm the structure of these ZnO nanoparticles. The IR absorption peak below 480 cm-1 and the XRD pattern showed all the peaks in the diffraction diagram, revealing the formation of ZnO-NPs. FE-SEM images showed various morphologies of ZnO-NPs and they have been found to be separated from the agglomerated clusters. Conclusion:: The characteristic results have revealed ionic liquids to have substantial effects on the size of the zinc nano-species as well as provide the appropriate environment for the growth of the nanoparticles.

The use of phages for the biosynthesis of metal nanoparticles and their biological applications: A review.

Nowadays, the use of biological methods of synthesis of nanoparticles as substitutes for methods that use high energy and consumption of expensive and dangerous materials is of interest to researchers all over the world. Biological methods of synthesising metal nanoparticles are very important because they are easy, affordable, safe, environmentally friendly and able to control the size and shape of nanoparticles. One of the methods that is of interest today is the use of bacteriophages as the most abundant organisms in nature in the synthesis of metal nanoparticles. Nanomaterials biosynthesized from phages have shown various clinical applications, including antimicrobial activities, biomedical sensors, drug and gene delivery systems, cancer treatment and tissue regeneration. Therefore, the purpose of this review is to investigate the biosynthesis of metal nanoparticles with phages and their biomedical applications.